1. Field of the Invention
This invention relates to the field of microform cards of the microfiche, ultrafiche PCMI (TM) and similar types and to card viewers, printers, sorters and related optical equipment which receive microform cards for utilization.
2. Description of the Prior Art
In the field of optics and photography, the prior art includes the use of a film media supporting element such as a specially prepared glass surface, commonly having diffusing characteristics, located adjacent to a photographic image carrying member for the purpose of preventing Newton ring image formation. An example of this technology is found in the Emde "Anti-Newton Ring" glass sold by Emde Products Incorporated of 2040 Stoner Avenue in Los Angeles, California, for use with color slides and lantern slides in projecting equipment.
Although Emde glass technology does not provide optical interfaces which are free of Newton ring color bands, in the general purpose photography field, it is found that incorporation of diffusing elements in a microform card system is attended by undesirable features such as reduced optical efficiency and blurring of the optical image.